Endocrine Abstracts

Introduction: Parathyroid carcinoma (PTHCa) is a rare malignant tumour which, although associated with higher calcium and parathyroid hormone (PTH) levels at presentation and younger age group, can only be diagnosed on histological basis. Recent studies have shown a logarithmic formula (using Calcium, PTH and age) can predict PTHCa if it scores more than 5%, with a sensitivity and specificity of 100% and 30% respectively. We describe a case where application of similar formula helped predict parathyroid carcinoma preoperatively.

Case: A 43 years old man presented with new onset worsening lethargy, thirst and constipation over last 2 weeks. History was not suggestive of any previous medical problems or exogenous supplements. On examination, a soft mass was palpable in the left anterior triangle of the neck with no other pertinent clinical findings. His initial investigations showed corrected calcium level 4.74 mmol/L. PTH 35.2 pmol/L, Urea 9.5 mmol/L and Creatinine 206 umol/L. He was treated with aggressive intravenous hydration and zolendronate which improved his calcium levels to 2.79 mmol/L with normalization of renal function. His neck ultrasound showed 4.2×6.7 cm cystic parathyroid mass and he was referred for surgical removal.

Discussion: Early detection of PTHCa and differentiating it from parathyroid adenoma affects the surgical technique, waiting time as well as long-term patient outcome and applying the non-invasive formula by Karakas et al. can help aid in the preoperative diagnosis of PTHCa.

Reference: Karakas E, Müller HH, Lyadov VK, et al. Development of a Formula to Predict Parathyroid Carcinoma in Patients with Primary Hyperparathyroidism. World J Surg; 2012 36:2605–11.